1. Field of the Invention
The present invention relates to a split ring spring for snap fasteners such as snap-fit buttons, and a method of manufacturing such split ring spring.
2. Prior Art
As shown in FIG. 5 of the accompanying drawings, a snap-fit button 1 for garment fabrics is composed of a male or stud member 2 and a female or socket member 3 which are attached to a pair of garment fabric pieces C, C, respectively, by means of tacks 4, 5. The socket member 3 includes a split ring spring 6 into which a body 7 of the stud member 2 is snap-fitted to connect the two fabric pieces C, C.
In the manufacture of such ring spring 6, it has been customary practice to first wind a continuous wire W of resilient material around a mandrel 8 and then sever an individual turn of the coiled wire W by a cutter 9 which is reciprocably movable in a direction perpendicular to the longitudinal central axis of the mandrel 8, as shown in FIG. 6.
With this severance, there are produced two burrs 10a, 10b projecting respectively radially inwardly and outwardly from the severed opposite ends of a finished ring spring 6. If the ring spring 6 having such burrs 10a, 10b were incorporated in the socket member 3 as shown in FIG. 5, the stud body 7 would be scarred or damaged by the radially inwardly projecting burr 10a when the stud and socket members 1, 2 are snapped together. The stud member 1 thus scarred is unsightly in appearance. Another problem is that the burrs 10a, 10b hinder smooth coupling and uncoupling of the stud and socket members 1, 2.